Among conventional chabazite-type zeolites, catalysts having copper supported thereon in such an amount that the atomic ratio of copper relative to aluminum exceeds approximately 0.25 are already known (see Patent Document 1).
Further, among conventional chabazite-type zeolites, catalysts having an SiO2/Al2O3 molar ratio of 15 to 50 and an average particle size of at least 1.5 μm are also known (see Patent Document 2).